Cycloalkanobenzofurans 3a-d were prepared in a one-pot reaction from trimethylhydroquinone (1) with cycloalka-1,3-dienes 2a-d. Acid-catalyzed reaction of 1 and cycloalkane-1,2-diols 4c-h afforded spiro compounds 6a-c. The mechanism of these novel ring-contraction reactions is also discussed.